Rising scrap consumption in China is leading steel mills to set up RHF to extract zinc and iron oxide from the dust and slime
RHF: Can be a Game Changer ?
RHF technology uses pulverized coal as a reducing agent and coal gas as the fuel. Carbon-contained pellets, too, can be used. This fast direct reduction device is currently the most preferred when it comes to treating and recovering zinc and lead-contained dust.
The two principal functions of RHF are: treating steel plant dust containing zinc and special or hard-reducing iron ore such as V & Ti-contained iron ore, red soil nickel ore, hematite and limonite; and treating ferrous slag like copper slag and nickel slag and smelting iron making.
China Steel Mills converging for RHF
Chinese mills are catching up RHF technology in order to get maximum value from steel wastes. In June, 2015 Yanshan Iron and Steel of the Hebei Iron and Steel Group successfully accomplished the hot run test of the production line of its RHF. Currently, the production line has reached its designed output, production status is stable and every working procedure is running well. Research carried out by the China-based Chongqing Iron and Steel Design Institute (CISDI) shows the plant can dispose of about 200,000 tons of dust from the BF and RHF and obtain about 140,000 tons of metalized pellets, 5,000 tons of zinc oxide dust and 130,000 tons of steam, thereby achieving a high economic and environmental value.
Technical knowhow is fast gathering momentum, as is evident from the way China is investing in recycling technologies. It deserves mention that the Chinese state-owned enterprise, Central Iron & Steel Research Institute (CISRI) has carried out many successful RHF experiments as regards dust, iron ore and ferrous slag treatments. The results have been impressive. Moreover, CISRI has built equipment for semi-industrial experiments. It has finished the Rizhao RHF production line, which shows noteworthy achievements in terms of low cost, quality production and productivity volumes. It has treated 2×0.2 million tons of zinc-bearing dust each year and the metalized pellets are used as converter coolants, while the zinc-rich dust is sold out. The RHF uses producer gas as fuel, and the exhaust system is equipped with air and coal gas heat exchanger.
To ensure resource efficiency and to sustain manufacturing economies of scale, steel industry experts are relying on recycling technologies more than ever before and more & more such path-breaking technologies will soon be adopted in other parts of the world.
Explore RHF technologies at SteelVia- The Global Steel Innovations Forum,on 25-27 Sep, 2018 Le Meridian, Dubai by Dr Xu Haichuan, Professor at the Department of Advanced Material, China Iron and Steel Research Institute (CISRI), will deliver an in depth talk on the future of RHF technology.